The invention relates to a method for setting a system for projecting an image onto a relief projection surface. Another subject of the invention is a method for displaying an image on this relief projection surface and a system for displaying a three-dimensional image. Finally, also the subject of the invention is an information storage medium for the implementation of the preceding methods.
A “relief” projection surface here describes a surface which is not contained in a plane. Such a relief surface therefore has bumps or hollows, the depth or the height of which relative to a median plane is at least greater than 5 mm and, typically, greater than 1 cm or 5 cm. The median plane is the plane which minimizes the sum of the heights and depths of all the reliefs of the projection surface. Typically, such a projection surface is dished so as to be primarily concave or convex. This projection surface is borne by a three-dimensional screen.
The term “three-dimensional” describes an object or a surface for which, regardless of the reference frame considered, the position of each point of this object or of this surface is defined unambiguously by three coordinates x, y and z along three non-coplanar axes of this reference frame, none of these coordinates being a constant.
The systems for displaying an image on a relief projection surface have in particular been developed to allow for the rapid production of prototypes. For example, such a system is described in the following article:
J. C. Verlinden, A. de Smit, A. W. J. Peeters, M. H. Van Gelderen, Development of flexible augmented prototyping systems, Delft University of technology.
As indicated in this article, one of the difficulties is that it is difficult to set the display system so that the projected image which is in two dimensions, is displayed correctly on the relief surface. More specifically, the difficulty stems from the fact that the image has to be projected very precisely so that the pixels of the image in two dimensions designed to illuminate a particular relief pattern of the three-dimensional screen actually illuminate this particular pattern and not another area of the three-dimensional screen.
Various setting methods have been developed. Most of these methods are manual and therefore take time.
The applicant has also considered an automatic setting method consisting in measuring, using an instrument, the position of the three-dimensional screen relative to the projector to then be able to compute the relationship which links each pixel of the image in two dimensions to a relief of the three-dimensional screen. This method entails knowing very accurately the position of the projector in relation to the position of the instrument for measuring the position of the screen. Now, in practice, it is not easy to fairly accurately position the measuring instrument relative to the projector.
Moreover, it is desirable to enable a user, in the simplest possible way, to select a particular position on the projection surface to automatically trigger, in response, an action.
Prior art is also known from:                Ramesh Raskar et al, Shader Lamps: Animating Real Objects with Image-Based Illumination, Proceedings of the Eurographics Workshop on Rendering, 25 Jun. 2001, pages 1-10,        Morishima S et Al, Hypermask: Talking head projected onto moving surface, Proceedings 2001 International Conference On Image Processing, vol. 3, 7 Oct. 2001, pages 947-950,        PIPER B et Al, Illuminating Clay: A 3-D Tangible Interface For Landscape Analysis, CHI 2002 Conference Proceedings. Conference on Human Factors in Computing Systems. 20 Apr. 2002, pages 355-362,        WO2010/102288A2,        Bennett E et Al, The effect That Touching a Projection Augmented Model Has on Object-Presence, Information Visualisation, 2005. Proceedings, Ninth International Conference On, 6 Jul. 2005, pages 790-795,        FREDERIC DELAUNAY et Al, A study of a retro-projected robotic face and its effectiveness for gaze reading by humans, Human-Robot Interaction (HRI), 2010 5th ACM/IEEE International Conference On, 2 Mar. 2010, pages 39-44,        HRVOJE BENKO, ANDREW D. WILSON, PATRICK BAUDISCH: Precise Selection Techniques for multi-touch screens, ACM, 22 Apr. 2006, pages 1263-1272.        